256417920 has 512 divisors, whose sum is σ = 1057536000. Its totient is φ = 58060800.

The previous prime is 256417907. The next prime is 256417921. The reversal of 256417920 is 29714652.

256417920 is a `hidden beast` number, since 2 + 5 + 641 + 7 + 9 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (256417921) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3611485 + ... + 3611555.

It is an arithmetic number, because the mean of its divisors is an integer number (2065500).

Almost surely, 2^256417920 is an apocalyptic number.

256417920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 256417920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (528768000).

256417920 is an abundant number, since it is smaller than the sum of its proper divisors (801118080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

256417920 is a wasteful number, since it uses less digits than its factorization.

256417920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 111 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 256417920 is about 16013.0546742338. The cubic root of 256417920 is about 635.3057572305.

The spelling of 256417920 in words is "two hundred fifty-six million, four hundred seventeen thousand, nine hundred twenty".